Abstract
Irrigation delivery systems were studied in the Punjab Province of Pakistan. The following physical factors influencing water delivery were considered: flow rate (usually unregulated), cross sections (great variation, many too rough or too shallow), hydraulic radius (randomly selected), slope (generally very small), seepage rate (high infiltration in the silty loam, banks riddled with insect and rodent burrows), roughness, and management (poor because of lack of knowledge and technical assistance). Many alternatives were examined. Farmer clearing and maintenance and reconstruction of earthen channels is very beneficial, with benefit: cost ratios of 2.9 to 17.6. Total system improvements had the highest ratios. Brick-masonry canal lining is not economical. Soil-cement lining is not cost effective without total system improvement. Side lining required improvement of the field ditches. Land leveling is valuable when combined with side lining. (Cassar-FRC)